Northern Chad a part of French West Africa?

Jun 2013
6,395
USA
#1
So Chad was definitely a part of French Equatorial Africa along with Ubangi-Shari, French Congo, and Gabon. However many maps of Africa in pre-ww1 times show the northern half of Chad as a part of French West Africa. I have not been able to find any information on this and was wondering if anyone had an explanation.